The literal point is that "talking too loudly" is such an arbitrary threshold that it is unfit to complain about. What if they talked so "loudly" because one of them had a hearing problem, what if they were talking at an "appropriate" volume but the ambient noise went down all of a sudden, etc., etc.
And the people have right to complain about the people complaining who have a right to..., like I said, circular argument.
btw, I'm currently reading Good-bye to all That, and um like the introduction (written by someone else) is literally accounting for what happens in the novel, explaining certain things in their context, and adding some other context for events in the book. Does the introduction count as a spoiler according to you?
Let me spell it out for you in the form of a play:
Person 1 (talking loudly): Hey did you see Game of Thrones last night? I can't believe Jon Snow is now a werewolf vampire hybrid!
(Few minutes later)
Person 2: Hey, can you quieten it down a tad when talking about GoT? I'm not able to watch the episodes live and I can hear you talking from way over the room.
Person 1: Ah, sorry, yeah I'll be more considerate in the future.
That's all I'm saying people should do. Person 1 should be a bit empathetic if called out and Person 2 shouldn't be barging into other people's conversations shouting and raving.
The free speech argument isn't circular because everyone has the right to say anything. Person 1 had the right to talk loudly and Person 2 had the right to call him out on it, trying to police one or the other is pointless as everything is taken on a case by case basis.
As for you reading the book, of course it's not a spoiler. If the author decides that their story isn't one that really needs that surprise then that's on them. However, not every piece of media is Good-bye to all That, most pieces of media don't start out with a Shakespeare-style sonnet saying exactly what'll happen (Shakespeare never really did that either, he just gave the general plot summary and didn't go into details). Applying one example to the entirety of media is not an argument. That and you can't say you care about people spoiling you intentionally and then use arguments like this to discredit people's feelings on all spoilers, it's trying to have your cake and eat it too.
That simply isn't true. Not caring about spoilers is not only perfectly possible, historically it's the norm. We talk of Jekyll and Hyde personalities even though this is a major spoiler for Robert Louis Stephenson's novel, we'll call a trap disguised as a gift a Trojan horse, a problem that is so costly to deal with you'll wish you had just ignored it is a tar baby, and in case you think this is restricted to old material I'll remind you of Luke's parentage and a dozen other plot features that have entered common folklore.
Spoiler sensitivity as a powerful force is a new and, as far as I'm concerned, unwelcome feature of popular culture. We had this discussion on Wikipedia a while back and, believe me, it took a serious effort to get all those spoiler tags removed. People were even slapping spoiler tags on the likes of the Three Little Pigs.
See above, you can't apply what some spoilers have become to the entire lexicon of media. Knowing Vader is Luke's father or that Jekyll is Hyde does not mean you're liable to shout out who dies in the latest episode of GoT or who the killer is in the latest murder mystery, they're nothing alike. However, if you time travelled back to 1886 or 1980 and told someone who cared about those things you'd get rightfully criticised for it.
Who have you been talking to that people are consistently, openly lying to your face about something as low-stakes as "I don't care about spoilers?"
Like, what?
"I don't care about spoilers."
"OK, that must mean you're fine being spoiled on the latest pieces of media."
"Oh no no I care about those spoilers."
That's what I'm talking about, and it's happened multiple times in this thread. People saying they don't care about spoilers when, in reality, they either don't care about others being spoiled or don't care about being spoiled in a certain way. Essentially, in my eyes, if you're going to say you don't care about spoilers you're lying if you then pick and choose what spoilers you care about.